03 Mountainer 4.6 motor

squeak93

15 Year Member
Jun 2, 2005
2,254
358
164
Joplin, Missouri
Ok, I just bought this 22k mile gem for 1k.(aluminum block ftw) Full motor, lower intake to pan obviously. My npi motor is stock and blown up so I figured this is my cheapest and best bet to get a pi swap and a good motor w/o having to jack with rebuilding and finding all the swap parts.

So my question is, Other than the front timing cover and a few sensors.... Should I expect any issues or just enjoy a nice easy motor swap? (I built 100% of my last pushrod motor, so not a newb here). Just trying to make sure I don't have any real suprises like valve covers not clearing or something stupid like that. Not done to much work to mod cars, always been foxes.
 
Not sure if you will have any suprises, I'm answering because I just recently purchased a 2004 Mountaineer with 35K miles. I do know the motor only has 239hp which is less than a PI Mustang's 260. I haven't really looked into the differences between the 2 engines yet so can't offer any advice yet. I'm still trying to get used to the vehicle and haven't ventured much into the engine compartment yet.
 
As far as I understand it, the difference is in the Tune and set up. The exhaust and trans/rear combo rob more from the exploders and mountainiers.

They way I understand it, beside from the Aluminum block, the motors are identical.

Anyone want to chime in there?
 
Looked mine over a bit, they are virtually identical. One minor difference is the alternators are different, at least the mounting is different so definetly a different alternator. Could have the same amperage, but I have no info available on that.

I'd say the major difference is in the tune and exhaust, since it goes to a single muffler. The hp difference is at the crank so no tranny or rear end to make a difference there (AWD is awesome though!). I hadn't noticed it was an aluminum block, thanks for pointing it out. :nice:

No matter what its got to be an upgrade over your NPI motor.
 
May look visually the same but my guess is that the cams and/or heads have some differances in them and that is where the additional HP from the Mustang comes. Again, I am not a 4.6 expert (5.0L only) but it makes sense.